#include <bits/stdc++.h>
#define rep(i,j,k) for(int i=(j);i<=(k);i++)
#define per(i,j,k) for(int i=(j);i>=(k);i--)
#define uint unsigned int
#define ll long long
#define ull unsigned long long
#define db double
#define ldb long double
#define pii pair<int,int>
#define pll pair<ll,ll>
#define mkp make_pair
#define eb emplace_back
#define SZ(S) (int)S.size()
//#define mod 998244353
//#define mod 1000000007
#define inf 0x3f3f3f3f
#define linf 0x3f3f3f3f3f3f3f3f
using namespace std;

template <class T>
void chkmax(T &x,T y){
	if(x < y) x = y;
}

template <class T>
void chkmin(T &x,T y){
	if(x > y) x = y;
}

inline int popcnt(int x){
	return __builtin_popcount(x);
}

inline int ctz(int x){
	return __builtin_ctz(x);
}


/*ll power(ll p,int k = mod - 2){
	ll ans = 1;
	while(k){
		if(k % 2 == 1) ans = ans * p % mod;
		p = p * p % mod;
		k /= 2;	
	}
	return ans;
}*/
int T,n,m;
int G[105][105],deg[105];

queue <int> Q;
bitset <105> dp[105];
int ans[105];
void solve(){
	scanf("%d%d",&n,&m);
	rep(u,1,n){
		fill(G[u],G[u] + n + 1,0);
		deg[u] = 0;
		dp[u].reset();
		dp[u].set(u);
	}
	rep(i,1,m){
		int u,v;
		scanf("%d%d",&u,&v);
		G[u][v] = 1;deg[u]++;
	}
	rep(u,1,n) if(!deg[u]) Q.push(u);
	int sz = 0;
	while(!Q.empty()){
		int u = Q.front();
		Q.pop();
		sz++;
		rep(v,1,n){
			if(!G[v][u]) continue;
			dp[v] |= dp[u];
			deg[v]--;
			if(!deg[v]) Q.push(v);
		}
	}
	if(sz < n){
		rep(u,1,n) printf("0");
		printf("\n");
		return;
	}
	rep(u,1,n) ans[u] = dp[u].count() <= (n / 2 + 1);

	rep(u,1,n){
		deg[u] = 0;
		dp[u].reset();
		dp[u].set(u);
	}
	rep(u,1,n){
		rep(v,1,n) if(G[u][v]) deg[v]++;
	}
	rep(u,1,n) if(!deg[u]) Q.push(u);
	while(!Q.empty()){
		int u = Q.front();
		Q.pop();
		rep(v,1,n){
			if(!G[u][v]) continue;
			dp[v] |= dp[u];
			deg[v]--;
			if(!deg[v]) Q.push(v);
		}
	}	
	rep(u,1,n){
		ans[u] &= dp[u].count() <= (n / 2 + 1);
		printf("%d",ans[u]);
	}
	printf("\n");
}

int main(){
//	freopen("test.in","r",stdin);
	scanf("%d",&T);
	while(T--) solve();
	return 0;
}